ON THE SEASONAL VAEIATIONS OF TEMPEEATUEE. 



497 



Monthly Mea7is of Temperature Observations on the L^igg at Aymestry. 



Kennet. 



Observations on the Kennet at Marlborough were made by Mr. W. B. 

 Maurice and Mr. H. G. Maurice, acting for the Marlborough College 

 Natural History Society. The stream at the point of observation was 

 about 6 or 7 feet deep and about 24 feet in breadth, about 10 miles 

 from its source, and nearly 40 miles from its junction with the Thames. 

 The depth of water varied considerably on account of a weir about 

 quarter of mile down stream erected to supply a mill, and when the mill 

 was not at work the level was allowed to fall very low. 



The observations, shown in Curve XV., are remarkable in showing a 

 very much less range of temperature in water than air. While the 

 weekly means of air-temperature ranged from 30° to 70°, those of water- 

 temperature were confined between 40° and 55°. The river was always 

 cooler than the air in summer and warmer than the air in winter, being 

 at the same temperature in April and October. The record is unfortu- 

 nately somewhat irregular, but the main facts of annual change of tem- 

 perature are sufficiently outlined by it. 



Monthly Means of Temperature Ohservations on the Kennet at Marlhorougli. 



1891. 



